feat(es/minifier): Implement minifier

.github/.prettierrc

@@ -0,0 +1,4 @@
+{
+    "tabWidth": 2,
+    "useTabs": false
+}

.github/workflows/cargo.yml

@@ -117,6 +117,7 @@ jobs:
           - swc_ecma_dep_graph
           - swc_ecma_ext_transforms
           - swc_ecma_loader
+          - swc_ecma_minifier
           - swc_ecma_parser
           - swc_ecma_preset_env
           - swc_ecma_transforms

.gitmodules

@@ -1,3 +1,7 @@
 [submodule "ecmascript/test262-parser-tests"]
 	path = ecmascript/parser/tests/test262-parser
 	url = https://github.com/tc39/test262-parser-tests.git
+	shallow = true
+[submodule "vendor/terser"]
+	path = vendor/terser
+	url = https://github.com/terser/terser.git

.prettierrc

@@ -0,0 +1,4 @@
+{
+	"tabWidth": 4,
+	"useTabs": false
+}

common/src/eq.rs

@@ -21,6 +21,19 @@ impl EqIgnoreSpan for Span {
     }
 }
 
+impl<T> EqIgnoreSpan for [T]
+where
+    T: EqIgnoreSpan,
+{
+    fn eq_ignore_span(&self, other: &Self) -> bool {
+        self.len() == other.len()
+            && self
+                .iter()
+                .zip(other.iter())
+                .all(|(a, b)| a.eq_ignore_span(b))
+    }
+}
+
 impl<T> EqIgnoreSpan for Option<T>
 where
     T: EqIgnoreSpan,

ecmascript/Cargo.toml

@@ -14,6 +14,7 @@ all-features = true
 [features]
 codegen = ["swc_ecma_codegen"]
 dep_graph = ["swc_ecma_dep_graph"]
+minifier = ["swc_ecma_minifier"]
 parser = ["swc_ecma_parser"]
 transforms = ["swc_ecma_transforms"]
 utils = ["swc_ecma_utils"]
@@ -30,6 +31,7 @@ typescript = ["swc_ecma_transforms/typescript"]
 swc_ecma_ast = {version = "0.45.0", path = "./ast"}
 swc_ecma_codegen = {version = "0.55.0", path = "./codegen", optional = true}
 swc_ecma_dep_graph = {version = "0.25.0", path = "./dep-graph", optional = true}
+swc_ecma_minifier = {version = "0.1.0-beta.0", path = "./minifier", optional = true}
 swc_ecma_parser = {version = "0.57.0", path = "./parser", optional = true}
 swc_ecma_transforms = {version = "0.50.0", path = "./transforms", optional = true}
 swc_ecma_utils = {version = "0.36.0", path = "./utils", optional = true}

ecmascript/minifier/Cargo.toml

@@ -0,0 +1,35 @@
+[package]
+authors = ["강동윤 <[email protected]>"]
+description = "Ecmascript code minifier."
+documentation = "https://swc.rs/rustdoc/swc_ecma_minifier/"
+edition = "2018"
+include = ["Cargo.toml", "src/**/*.rs"]
+license = "Apache-2.0/MIT"
+name = "swc_ecma_minifier"
+repository = "https://github.com/swc-project/swc.git"
+version = "0.1.0-beta.0"
+
+[dependencies]
+fxhash = "0.2.1"
+log = "0.4"
+once_cell = "1.5.2"
+pretty_assertions = "0.6.1"
+regex = "1.5.3"
+retain_mut = "0.1.2"
+serde = {version = "1.0.118", features = ["derive"]}
+serde_json = "1.0.61"
+serde_regex = "1.1.0"
+swc_atoms = {version = "0.2", path = "../../atoms"}
+swc_common = {version = "0.10.8", path = "../../common"}
+swc_ecma_ast = {version = "0.45.0", path = "../ast"}
+swc_ecma_codegen = {version = "0.55.0", path = "../codegen"}
+swc_ecma_transforms = {version = "0.50.0", path = "../transforms/", features = ["optimization"]}
+swc_ecma_transforms_base = {version = "0.15.0", path = "../transforms/base"}
+swc_ecma_utils = {version = "0.36.0", path = "../utils"}
+swc_ecma_visit = {version = "0.31.0", path = "../visit"}
+
+[dev-dependencies]
+ansi_term = "0.12.1"
+swc_ecma_parser = {version = "0.57.0", path = "../parser"}
+testing = {version = "0.10.2", path = "../../testing"}
+walkdir = "2.3.1"

ecmascript/minifier/README.md

@@ -0,0 +1,7 @@
+# Minifier
+
+EcmaScript minifier for the swc project. This is basically a port of terser.
+
+## Copying tests
+
+Replace the content of `terser/test/compress.js` with it of `scripts/compress.js` and run `npm run test:compress`

ecmascript/minifier/scripts/add-golden.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+#
+# This script automatically add tests to golden.
+# Note that this is append-only.
+set -eu
+
+cargo test --test compress \
+  | grep 'js .\.\. ok$' \
+  | sed -e 's!test fixture_terser__compress__!!' \
+  | sed -e 's! ... ok!!' \
+  | sed -e 's!__!/!g' \
+  | sed -e 's!_js!.js!' \
+  >> tests/golden.txt
+
+./scripts/sort.sh

ecmascript/minifier/scripts/ignore.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -eu
+
+cargo test --test compress $1 \
+  | grep 'js .\.\. FAILED$' \
+  | sed -e 's!test fixture_terser__compress__!!' \
+  | sed -e 's! ... FAILED!!' \
+  | sed -e 's!__!/!g' \
+  | sed -e 's!_js!.js!' \
+  >> tests/ignored.txt
+
+./scripts/sort.sh

ecmascript/minifier/scripts/jsprops.js

@@ -0,0 +1,47 @@
+// Run this script to build jsprops.json
+
+const fs = require('fs')
+
+// Compatibility fix for some standard defined globals not defined on every js environment
+var new_globals = ["Symbol", "Map", "Promise", "Proxy", "Reflect", "Set", "WeakMap", "WeakSet"];
+var objects = {};
+var global_ref = typeof global === "object" ? global : self;
+
+new_globals.forEach(function (new_global) {
+    objects[new_global] = global_ref[new_global] || new Function();
+});
+
+const addedProps = new Set();
+
+const add = propName => addedProps.add(propName);
+
+[
+    "null",
+    "true",
+    "false",
+    "NaN",
+    "Infinity",
+    "-Infinity",
+    "undefined",
+].forEach(add);
+[ Object, Array, Function, Number,
+  String, Boolean, Error, Math,
+  Date, RegExp, objects.Symbol, ArrayBuffer,
+  DataView, decodeURI, decodeURIComponent,
+  encodeURI, encodeURIComponent, eval, EvalError,
+  Float32Array, Float64Array, Int8Array, Int16Array,
+  Int32Array, isFinite, isNaN, JSON, objects.Map, parseFloat,
+  parseInt, objects.Promise, objects.Proxy, RangeError, ReferenceError,
+  objects.Reflect, objects.Set, SyntaxError, TypeError, Uint8Array,
+  Uint8ClampedArray, Uint16Array, Uint32Array, URIError,
+  objects.WeakMap, objects.WeakSet
+].forEach((ctor) => {
+    Object.getOwnPropertyNames(ctor).map(add);
+    if (ctor.prototype) {
+        Object.getOwnPropertyNames(ctor.prototype).map(add);
+    }
+});
+
+const propsJSON = JSON.stringify([...addedProps].sort(), null, 4)
+
+fs.writeFileSync(__dirname + '/../src/lists/jsprops.json', propsJSON)

ecmascript/minifier/scripts/run.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+#
+# This script exists to prevent regression.
+#
+# This script invoked tests two time.
+# For first, it runs tests in no-regression mode.
+# In the mode, only tests listed in tests/golden.txt will be tested.
+# 
+# For second invokation, arguments are passed to cargo test so the user can
+# filter tests.
+#
+set -eu
+
+if [ -z "$@" ]; then
+    ./scripts/sort.sh
+
+    export RUST_LOG=swc_ecma_minifier=trace
+
+    GOLDEN_ONLY=1 cargo test --test compress
+fi
+
+cargo test --test compress $@

ecmascript/minifier/scripts/sort.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -eu
+
+# Fix sorting differences between Linux and Mac
+export LC_ALL=C
+
+cat tests/golden.txt | awk NF | sort | uniq | awk '{$1=$1};1' | uniq | sort > tests/golden_sorted.txt
+mv tests/golden_sorted.txt tests/golden.txt
+
+cat tests/ignored.txt | awk NF | sort | uniq | awk '{$1=$1};1' | uniq | sort > tests/ignored_sorted.txt
+mv tests/ignored_sorted.txt tests/ignored.txt